This project examines the epidemiological distribution of depression in a large, metropolitan area and the role of social support systems in the occurrence and distribution of this condition as well as the help-seeking patterns of those with and without symptoms. In addtion, we propose to investigate the role of life changes and events social support systems, physical illness, and psychiatric symptoms of depression will be examined. With the use of a prospective study design, a random sample of 1,000 adults, representative of the Los Angeles County population, will be initially interviewed in a household survey and followed up quarterly by telephone interviews. The final interview will be either a face-to-face or telephone interview, depending upon random assignment. A control group of 250 additional persons will be used at the final interview to investigate panel effects. The major instrument for classifying depression will be the NIMH CES-D scale. This project will examine the role of social support systems on the use or non-use of community mental health and general medical resources by individuals identified as depressed. The relationship between cigarette smoking, alcohol consumption, and use of medications and depressive symptomatology will be examined.